Supports for suspending fluorescent lighting fixtures



Sept 30, 1958 M. H. KRUGER SUPPORTS FOR SUSPENDING FLUORESCENT LIGHTINGFIXTURES 3 Sheets-Sheet 1 Filed Dec. 23, 1955 SUPPORTS FOR SUSPENDINGFLUORESCENT LIGHTING FIXTURES Filed Dec. 25, 1955 M. H. KRUGER Sept. 30,1958 3 Sheets-Sheet 2 .IIIIVII I! I lllllllllll 4 INVENTOR. Mae eaflaw/9y 591/45 577'0F/Vfy .r' n Y J Sept. 30, 1958 M. H. KRUGER2,854,205

SUPPORTS FOR SUSPENDING muomzscsm LIGHTING FIXTUR 3 Sheets-Sheet 3 FiledDec. 23, 1955 United States r SUPPORTS FOR SUSPENDING FLUQRESCENTLHGHTENG FEXTURES Michael Henry Kruger, Chestnut Hill, Mass, assignor toA. L. Smith Iron Company, Chelsea, Mass, 2 vcorporation of MassachusettsApplication December 23, 15 55, Serial No. 555,,il43

3 Claims. ((11. 248-343) This invention relates to fluorescent lightingfixtures in general, and more specially to supports for suspendingfluorescent lighting fixtures to a building structure.

Among the-objects of the present invention, it is aimed to provide animproved support for suspending a fluorescent lighting fixture in aceiling or the like Where the building structure on which the supportrests consists in a pair of parallel rafters, cross beams, or the like,where the lighting fixture is disposed between such rafters and thedistance between such rafters may vary, where the depth of projectionupward between the rafters may vary according to the architectsspecifications, and where the strength of the rafters may vary dependingupon the ceiling construction. In view of the foregoing, it is aimed toprovide an improved support which (1) is adjustable and yieldablelaterally, (2) is adjustable vertically, and (3) will reduce to aminimumany angular torsional strain on the rafters.

These and other features, capabilities and advantages of the inventionwill appear from the subjoined detailed description of specificembodiments thereof illustrated in the accompanying drawings, in which:

Fig. 1 is a front elevation of one embodiment of the improved supportdiagrammatically showing the trolfer and lighting fixture connectedthereto.

Fig. 2 is a plan View of the support shown in Fig. 11.

Fig. 3 is a transverse section of one of-the connectors shown in Fig. 1.

Fig. 4 is a fragmental perspective of the support shown in Fig. l withthe troffer and lighting fixture shown diagrammatically.

Fig. 5 isa front elevation of the support shown in Fig. 1 before thetrofier .and lighting fixture are connected thereto.

Fig. 6 is an end elevation of the support shown in Fig. 5.

Figs. 7, 8, 9 and 10,-are fragmental front elevations of fourembodiments of, connectors differing from one another and from theconnector shown in Fig. 1.

Fig. 11 is an enlarged fragmental section of a part of the. bridge showninFig. 5

Fig. 12 isa fragmental section on the line 1212 of Fig-11.

Fig. 13 is a fragmental section similar to Fig. 11 with the link shownin outwardly inclined position as distinguished from the inwardlyinclined position of the link shown in Fig. 11.

The improved support shown inFig. .1 consists essentially in theone-piece metal bridge 1, L-shaped brackets 2 and '3, troffer-engaginglinks 4 and 5, and the rafterengaging connectors 6 ,and -7. Therafterrengaging ,connectors 6 and '7 adjustably connect thehorizontallyextending rafters, such as theT-bars 3 and 9 to the Lashaped brackets 2and 3;,theginwardly and-horizontally extending limbs lfland llofzthe:brackets.2 and 3, respectively, slidably and adjustably connecttheends ofthe bridge 1 in place; and thedepeuding links and e pivotallycon- 2,854,205 Patented Sept. 30, 195.8

limbs 1t) and 11 and the ends of the bridge 1 provides for longitudinaladjustment of the support in a lateral direction of the trotfer 12; theadjustable connection between the connectors 6 and 7 and the verticaldownwardly extending limbs 13 and 14,, respectively, of the brackets 2and 3, provides for vertical adjustment of the support and therebyvertical adjustment of the trofier 1 2 relative to the ceiling; and thebridge 1 in cooperation with the brackets 2 and 3 reduces to a minimumany angular torsional strain on the rafters, such as the T-bars "8, and9. Furthermore, the limbs 10 and 11 are 'slidable. relative to the endsof the bridge 1. This slidable relationship together with the pivotalconnection of the links ,4 and 5 carrying the troffer 12 relative to thebridge 1, will compensate for any building sway due to wind storms andthe like, especially when the lighting fixtures are equipped in theupper floors of tall buildings; will compensate for expansion andcontraction due to temperature changes; and will compensate for anystructural reformations caused by settling of the building; and willreduceto a minimum any angular torsional strains that might betransmitted to the rafters, such as the T-bars 8 and 9 so that anyinjury due to twisting or the like to (the rafters, such as the T-bars'8 and 9, especially if composed of light weight material, will beentirely avoided.

Another advantage of this combination of bridge 1, L-shaped brackets 2and 3, and trofier-engaging links 4 and 5, resides in the fact that itis extremely flexible so that it can be secured to practically anunlimited number .of ceiling constructions, not only to a ceilingconstruction equipped with bars, such as the T-bars 8 and 9, but alsowith ceiling constructions such as those illustrated in Figs. 7, 8, 9and 10.

More specifically, the bridge 1 comprises a web 15 which has anintermediate portion 16,.two downwardly inclined or curved portions 17and 18 and two outwardly extending ends or portions 19 and 29substantially parallel to the intermediate portion 16. Preferably theintermediate portion 16 has formed therein an oblong longitudinallyextending opening 21 to clear the supporting rod 22 which extends fromthe ceiling structure down to the trofier 12 and is connected thereto.Preferably also in the interest of rigidity and reenforcement, the web15 has upwardly extending flanges 121 and 122 extending the full lengthof the web 15 from the lateral edges of the portions 16, 17, 18, 19 andZil.

In the curved portions '17 and 18 there are provided laterally extendingopenings 23 and 24, respectively, through which extend the links 4 and5, respectively. Each of thelinks 4, '5, see Fig. 11, comprises a shank25 having an outwardly extending plate or lip 26 at its upper end and ahook or hook formation 27 at its lower end consisting of an outwardlyextending projection or portion 28, a downwardly extending portion 29,and an inwardly extending portion 30 extending to and beyond the shank25 and terminating in an upwardly inclining lip 31. The lower faces ofthe portions 17 and 18 form abutments for the springs 32. Each spring 32is tensed between a portion 17, 18 and the upper face of the portion 28.The shank 25 as aforesaid extends through the opening 23, 24 'with theportion 26 disposed above the upper face of the portion 19, 20, and theportions 30, 28 and 26 and the portion 19, 20 having openings inalinement with one another to receive the screw 33 with the head 34engaging the lower face of the portion 30 and the nut 35screw-threadedly connected to the screw 33 abutting against the upperface of the portion'26. In order to aid in tilting the links 4 and 5inwardly as shown in Fig. 5, the plate 36 isprovided which has adownwardly extending flange 37 which is wider than the width of theopening 23,24 so that its ends engage the lower face of the portion 17,18, and the plate 36 rests on the upper face of the portion 19, 26. Thisplate 36 has an opening formed therein with the side pressed upwardly toform the upwardly extending flange 38, the edges of the opening and theinner face of the flange 38 being threaded to receive the screw-threadedshank portion 39 of the screw 33. In this way the plate 36 is rockablysecured to the portion 17, 18 with the flange 37 engaging the lower faceof the portion 17, 18, and the plate 36 engaging the upper face of theportion 19, 20, and the link 4, being pivotally mounted relative to theportion 19, 20 when the upper edges of the flange 37 act as the fulcrumduring the pivotal movement of the link 4, 5 rela tive to the bridgeportion 19, '20. The screw 33 will be screwed up into the plate 36 asufl'icient distance to cause the angle between the plate 36 and itsflange 37 freely to engage the upper face of the bridge portion 17, 18,and the springs 32 will normally swing the lower ends of the links 4 and5 toward one another into the full line position shown in Fig. 5, wherethe plate portion 36 will rest flat on the bridge portion 19, 20. Thespring 32 will in turn yield and allow the outer portion of the plate 36to recede from the bridge portion 19, 20, when the link 4, 5 is swunginto the dotted line position shown in Fig. 5 and full line positionshown in Fig. 13. Although free movement of the link 4, 5 relative tothe bridge portion 19, 20 is necessary, it is desirable that the lowerends of the links 4 and 5 be spaced a predetermined distance from thebridge 1 so that when the lower ends 138 and 139 of the trofier 12 reston the portions 39 of the links 4 and 5, they will conform to the levelpredetermined for the lower ends 138 and 139 of the trofler 12. When thetrofler 12 as aforesaid so rests on the links 4 and 5, it may swayslightly to accommodate movement of the building, particularly if thelighting fixture is installed in one of the upper stories of a tallbuilding, and in turn the links 4 and 5 may move toward or away from oneanother clue to expansion and contraction, bearing in mind the diiferenttemperatures to which the lighting fixture may be subjected not onlywhen illuminated as distinguished from being non-illuminated, but alsothe diiferent room temperatures to which the lighting fixture may besubjected from winter to summer and the like.

The lighting fixture 40 may be any of the well-known types, such asdisclosed in United States Letters Patent No. 2,597,875, which may beattached to the troffer 12 in the manner shown in this patent. In orderto ac commodate various widths between adjacent parallel rafters, suchas the T-bars 8 and 9 shown in Fig. 1, the bridge portions 19 and 20 ofthe bridge 1 preferably are each provided with a pair of elongated slots41, 41 and 42, 42, extending longitudinally to the bridge 1. Througheach of these pairs of slots 41 and 42 extend a pair of rivets 43, 43and 44, 44, respectively, the rivets 43, 43 being secured to thehorizontally extending limb of the bracket 2 and slidably mounted in theslots 41, 41, and the rivets 44, 44 being secured to the limb 11 of thebracket 3 and slidably mounted in the slots 42, 42. This slidablerelationship between the limbs 10 and 11 and the bridge portions 19 and20, respectively, not only allows for varying widths between adjacentrafters, such as the T-bars 8 and 9, but also to supplement the pivotalmountings of the links 4 and 5 to; accommodate diiferences intemperature to which the lighting fixture 40, trotfer 12, bridge 1 andbrackets 2 and 3 may be subjected, and also to the diiference intemperatures to which the T-bars 8 and 9 may be subjected. The bridge 1with its pivotally mounted links 4 and 5 and slidable mounting of thebrackets 2 and 3 relative to the bridge 1 all contribute, 1) to aflexible mounting which will accommodate itself to variations in widthbetween the rafters, such as the T-bars Sand 9, movement of the buildingv 4 due to wind storms and differences in temperature without anyresulting strain on any of the working parts of the mounting, and (2)also to reenforcing and bracing the brackets 2 and 3 so thatnotwithstanding the flexibility achieved by the combination aforesaid,including the bridge 1, brackets 2 and 3 and links 4 and 5, they willbar any torsional strain being transmitted to the rafters, such as theT-bars 8 and 9.

Due to the tendency in present building construction in the interest ofreducing weight and costs, in turn to reduce the weight and size of therafters, such as the T-bars 8 and 9, an increasing threat to twistingthese rafters resulting from the weight of the light fixture has beenencountered when the troifer 12 and lighting fixture .40

epended only upon the brackets 2 and 3 for support. A rigid bridgebetween the brackets 2 and 3 would invite other more serious risks.However, with the present flexible combination, including the bridge 1slidably connected to the brackets 2 and 3, and the links 4 and 5pivotally connected to the ends of the bridge 1 instead bf to the links4 and 5, not only would the torsional strains on the rafters, such asT-bars 8 and 9, be entirely ohminated, but the equally injurious strainsdue to a r1g1d bridge connecting the brackets 2 and 3 would bepositively eliminated.

Aside from the foregoing, the vertical limbs 13 and 14 of the brackets 2and 3 of this flexible bracing combination when provided with asuccesion of openmgs-143 and 144 lend themselves admirably toaccommodate any one of a number of connectors such as the connectors 6and 7 of Figs. 1, 2, 3 and 6, or the connectors and 145 shown in Figs. 7and 9, respectively, the connector 46 shown in Fig. 8, the connector 47shown in Fig. 10, or any number of any connectors without departing fromthe spirit of the present invention.

The connectors 6 and 7 are particularly adapted for the T-bar rafters 8and 9, respectively, and consist essentially of an outer bracket 48having a jaw 49'to engage the outer extension 50 of a T-bar, such as theT-bar 8. This jaw 49 has extending at right angles thereto the plate 51having inwardly extending flanges 52 and 53, see Figs. 1, 2 and 3, togrip the edges of the limb 13 of the bracket 2. On the plate 51 there ispivotally mounted the locking plate 54 whichhas an outwardly extendinggripping lip 55 and two inwardly extending prongs 56. The inwardlyextending prongs 56, 56 enter a pair of alined openings 143 and 144, seeFig. 6. Besides the outer bracket 48, this connector 6, 7 also has aninner bracket 57 having a jaw 58 to grip the inner extension 59 of theT-bar 8. This bracket 57 also has two upwardly ex-- tending flanges 60,60 which extend through an opening in the plate 51 and abut against thelimb 13. The limb 13 thus anchors the brackets 57 and 48 to one anotherand to the T-bar 8, and the prongs 56 of the plate 54 anchor thebrackets 48 and 57 to the limb 13.

In the embodiment shown in Fig. 7 the outer bracket 61 of the connector45 has a gripping jaw 62 to engage the outer flange 63 of the I-beam 64.This bracket 61 also has an upward extension 65 similar to the upwardextension 51 of the bracket 48 which has jaws 66 to engage the edges ofthe limb 67 similar to the limb 13 of the embodiment illustrated in Fig.6. The plate 65 has pivotally connected to it a plate 68, similar to theplate 54 of the embodiment illustrated in Fig. 6, which in turn hasprongs 69 to engage openings in the limb 67, such as the openings 143and 144 of the limb 13. This connector 45, however, dispenses with aninner bracket, such as the bracket 57 of the embodiment shown in Figs. 1and 2, and relies upon the limb 67 extending down and engaging the innerflange of the I-beam 64.' In this.

69 of the plate 68 in turn connect the limb 67 to the bracket 61 and theI-beam 64.

In the embodiment shown in Fig. 9 the connector 145,

substantially identical tothe connector 45 shown inFig. 7,

relies upon the limb 71 to engage theinner face of the U-shaped'rafter72 while the jaw engages the upper outwardly extending flange 74of-thisra-fter 72. In'turn, the connector 145- alsohas pivotallyconnected toit a'plate 75 similar to the plate 54 of the embodimentillustrated in Figs. 1, 2 and 6, which has prongs 76 extending intoopenings formed in the limb 71 similar to the prongs 56 of theembodiment illustrated in Figs. 1, 2 and 6.

The connector 46 shown in Fig. 8 differs from the connectors 45 and 145shown in Figs. 7 and 9 primarily in dispensing with the pivotallymounted plates 68 and 75, respectively, the connector 46 having anupwardly extendin g portion 77 through which extend two bolts 78 andnuts 79. These bolts 78 replace the prongs 69 of the plate 68 disclosedin Fig. 7. In turn the two bolts 78 enter a pair of openings in the limb80, such as a pair of openings 143 and 144 disclosed in Fig. 6.Preferably the bolts 78 yieldably connect the upwardly extending portion77 of the connector 46 to the limb 80 by having a coil spring 81 woundaround the shank of the bolt 78 and tensed between the upwardlyextending portion 77 and the nut 79. Preferably as shown, the head ofthe bolt 78 engages the inner face of the limb 80 and the spring 81engages the outer face of the upwardly extending portion 77 of theconnector 46. The connector 46 in the present instance has a jaw 82larger than the jaw 62 of the connector 45 to engage the outer extension83 of the U-shaped rafter 84. In assembled position as shown the limb 80extends down on the inside of the inner extension 85 of the rafter 84 sothat the bolts 78 not only connect the upwardly extending portion 77 tothe limb 80, but also anchor the jaw 82 and the limb 80 to the rafter84.

The connector 47 shown in Fig. 10, similar to the connector 46 shown inFig. 8 dispenses with the pivotally mounted plate of the connector 45shown in Fig. 7. In this embodiment the connector 47 consists of a plate86 having a jaw 87 at its lower end to engage the lower.

extension 88 of the rafter 89. The limb 90 engages the inner face of thearm 91 of the rafter 89. The plate 86 is provided with two bolts 92similar to the bolts 78 shown in Fig. 8 which extend through a pair ofopenings in the plate 86 and into a pair of openings in the limb 90similar to a pair of openings 143, 144 in the limb 13 illustrated inFig. 6. The heads of the bolts 92 engage the inner face of the limb 90.The bolts 92 in turn have nuts 93 on their outer ends between which andthe plate 86 are tensed the springs 94. Here, somewhat like thedisclosure of Fig. 8, the bolts 92 not only connect the plate 86 to thelimb 90 but anchor the connector 47 and limb 90 to the rafter 89 by theengagement of the extension 88 of the rafter 89 by the jaw 87 and by theengagement of the inner face of the plate 91 of the rafter 89 by thelimb 90.

Obviously two or more supports, each including a bridge 1, brackets 2and 3, links 4 and 5, and connectors 6 and 7, will ordinarily berequired to support an average lighting fixture, and the hook formationsat the lower ends of the links 4 and constituting the direct supportingengagement may assume formations other than the hook formations withoutdeparting from the general spirit of the invention.

It is obvious that various changes and modifications may be made to thedetails of construction without departing from the general spirit of theinvention as set forth in the appended claims.

I claim:

1. The combination of a support for a fluorescent lighting fixturehaving a trotfer, with two parallel horizontally extending rafters, saidsupport including a metal one-piece upwardly arched bridge havingupwardly extending reenforcing flanges at the longitudinally extendingedges thereof, two L-shaped brackets extending toward one another, eachhaving a horizontally extending limb and va downwardly extendinglimb,the ends of the bridge being slidably mounted on said horizontallyextending limbs, means fixing said bridge in adjusted position on thehorizontally extending limbs of said brackets, a row of openingsextending longitudinally on said downwardly extending limbs, twoconnectors, each connector attached to and securing one of saiddownwardly extending limbs to one of said rafters, means on saidconnectors entering one of the openings in said downwardly extendinglimbs to support the trolfer at the horizontal level corresponding tothe opening selected, depending links pivotally connected to said bridgeadjacent the ends thereof between said brackets and includingprojections beneath said bridge, a spring mounted on each link tensedbetween one of said projections and said bridge and normally urging saidlink to incline in wardly, and a portion at the lower end of each ofsaid links in supporting engagement with opposite sides of said troffer.

2. The combination of a support for a fluorescent lighting fixturehaving a trofier, with two parallel horizontally extending rafters, saidsupport including a bridge having a main portion, two horizontallyextending outer ends and outwardly extending and downwardly inclinedportions intermediate said main portion and said horizontally extendingouter ends, two brackets having inwardly extending limbsQthe outwardlyextending outer ends of said bridge resting upon and slidably mountedinto adjusted position upon said inwardly extending limbs, means fixingsaid bridge in such adjusted position on said inwardly extending limbs,two connectors, each connector. attached to and securing one of saidbrackets to one of said rafters, depending links pivotally connected tothe inclined portions of said bridge, a lip on each of said linksextending above the inclined portionsof said bridge, a projection oneach link beneath said bridge, a spring mounted on each link and tensedbetween its projection and said bridge normally urging the lip of eachlink into engagement with its adjacent inclined portion in turn normallyto incline its link inwardly, and means at the lower ends of said linksextending toward one another into supporting engagement with oppositesides of said troifer, said links being deflected outwardly by saidlighting fixture in opposition to said springs when the lighting fixtureis raised into supporting position and thereby positioning the lowerends of said links into supporting engagement with said troffer.

3. The combination of a support for a fluorescent lighting fixturehaving a troffer, with two parallel horizontally extending rafters, saidsupport including a one-piece metal bridge having a main portion,horizontally extending ends and outwardly and downwardly inclinedportions intermediate said main portion and said horizontally extendingends, two brackets each having an inwardly horizontally extending limband a downwardly extending limb, the horizontally extending ends of saidbridge resting upon, and slidably mounted into adjusted position on saidhorizontally extending limbs, means fixing said bridge in such adjustedposition on said horizontally extending limbs, two connectors, eachconnector attached to one of said rafters, means adjustably connectingsaid connectors to said downwardly extending limbs in a verticaldirection to assume a predetermined horizontal level, depending linksextending through. said bridge, lips on said links extending across thedownwardly inclined portions of said bridge, projections on said linksbeneath said bridge, springs on said links tensed between saidprojections and said bridge and normally urging said lips to cooperatewith said downwardly inclined portions of said bridge to incline saidlinks inwardly, and hook formations at the lower ends of said linksextending toward one another, said springs enabling said links to bedeflected outwardly when said lighting fixture is raised into engagementwith the same and urging said hook forma- .tul'e when position.

tion s into supporting engagement with said lighting fixsaid lightingfixture is raised into supporting References Cited in the file of thispatent -8 Walker et a1. Mar. 9,:1943 Terr Feb.. 15,11949 i Neysmith Mar.1 ,1949 Kruger 'May 27, v 1952 Janness June 16, 1953

